摘要
在波动方程叠前深度偏移中 ,速度是最关键的成像参数。首先分别对各种求取速度的方法进行了回顾和分析 ,然后按照判断速度正确性的不同标准将求取速度的方法分为 3类 :第 1类是以正演结果与实际数据的拟合最优作为判断标准 ;第 2类是以成像质量最优作为判断标准 ;第 3类是解析类型的方法。在此基础上提出 ,基于逆散射理论反演慢度扰动的方法和双域偏移成像方法在理论基础上有相当的一致性 ,所以在利用波形信息的高精度速度分析中可以将二者有机地结合起来。进而提出了一种将广义屏偏移与Born反演结合在一起实现速度分析的新思路。该方法保证了速度分析和偏移在理论基础上的一致性 ,能够充分发挥波动方程偏移在振幅保真方面的优势 ,是一种稳定的、高精度的速度分析方法。
Velocity plays a key role in each phase of seismic exploration and is also the most important parameter in wave equation pre stack depth migration. This paper firstly reviews and examines the existing velocity extraction methods. Different velocity extraction methods can be divided into three classes according to the criteria by which each method used to judge the validity of velocity. Class one is those which use optimal matching between forward modeling data and real data as the criterion. Class two is those which use optimal imaging as the criterion. Class three is consists of analytical methods. We then suggest that inversion methods for slowness perturbation by inverse scattering and migration methods realizing in dual domain can be integrated organically to form a new method for high precision velocity analysis because of consistency in their theory background. The new method combines generalized screen migration with Born inversion which guarantees the consistency between velocity analysis and migration in their theoretical basis and takes advantage of wave equation migration in preserving amplitude information. Therefore it is an accurate and stable velocity analysis method.
出处
《勘探地球物理进展》
2002年第3期20-26,共7页
Progress in Exploration Geophysics
基金
国家自然科学基金项目 (4 9894190 )
上海市重点学科资助项目。
